Good evening, Coyote and Guin. There’s an important bit of political science missing in what you folks said that we Americans overlook because both jobs are combined in the President: the separate jobs of the Head of Government and Head of State.
Most people see the Head of State job as a figurehead position, and there’s some truth in it – but “it’s important for what it doesn’t do,” so to speak. The loyalty and patriotism of the decent citizens is directed toward the state and the Head of State as its representative, not to the head of the government. In the case of a constitutional crisis, there are a half dozen or so residual powers that always vest in the Head of State, to be used only in such emergency situations – like dismissing the Head of Government when he refuses to resign and the Legislature refuses to support him, for example. Having the jobs separate also makes the task of a “man on horseback” in taking over the government entirely much more difficult – he not only has to become political leader but he has to convince people to abolish the separate job of Head of State and give that to him as well.
In addition, if the Head of State is elected for life or good behavior, or is a monarch, he or she builds up a fair amount of experience that is valuable to the decision-making process; his or her informal advice to the Government will not be disregarded by them.
In addition, the Head of State (and the Royal Family if you’re talking a monarchy) relieves the Head of Government of a lot of ceremonial but important duties. The Head of State has just got to show up at stuff like the opening ceremonies for the Olympics his country is hosting, the dedication of a memorial that commemorates something dear to his country’s heart, etc. It’s useful if that’s not also the guy who is keeping the government running on an even keel – the Head of Government.
Finally, having a separate Head of State makes the job of the other party much easier. It’s tough to draw the line between GWB as head of the Republican Administration, to whom all Democrats, Libertarians, and Greens owe a principled loyal opposition, and GWB as the President behind whom all Americans need to rally in time of crisis. And unscrupulous Presidents of both parties have in the past made that trick nigh onto impossible by “switching hats” on the Opposition. It’s much easier to make speeches in opposition to Tony Blair or John Major while standing foursquare for Queen and Country.
You’ll find that most of the European Parliamentary monarchies and republics preserve this distinction for precisely these reasons, though in some cases (e.g. Sweden) the residual political power is absent or negligible.
E2R does have a significant job to do, although I think it’s a reasonable question whether a cost/benefit analysis on the Monarchy would be favorable.